1. Field of the Invention
This invention relates to installing sections of underground piping, and more specifically, to a new tool for realigning a coring rod.
2. Description of Related Art
Methods and apparatuses have been developed to allow for the laying of underground piping, which is to run substantially parallel to the surface which it is under, without having to first dig up the surface under which the piping will ultimately lie. Generally, those methods and apparatuses involve installing the piping horizontally underground, between two pits, an entry pit and an exit pit, that flank the surface area under which the piping is to be horizontally laid. A recently invented method of laying horizontal underground piping, without digging up the surface under which it is to be laid, is disclosed in co-pending patent application no. 08/320,751 one of the components used in co-pending patent application no. 08/320,751 is a coring rod. As explained in application no. 08/320,751, initially, from the entry pit at one end of the site under which the piping is to be laid, at the desired depth of the center of the piping tunnel, a pilot rod is horizontally inserted into the site, and pushed through the site until part of it extends into the exit pit at the other side of the site. A coring rod must then be pulled back through the site, through the tunnel hole that has been made in the site by the pilot rod.
It can happen that as the pilot rod was initially being pushed through the site, from the entry pit to the exit pit, that it encounters underground rocks, or other harder areas along its path under the site, or that it encounters unusually soft areas, any of which will cause the pilot rod to deviate from its anticipated path under the site. When that happens, the pilot rod enters the exit pit at a point that is either horizontally or vertically, or both horizontally and vertically, out of line with the point in the entry pit at which it entered the site. The pilot rod, and the tunnel it created under the site, are no longer in line with the anticipated tunnel that it was to have created under the site. When the coring rod is pulled back through the pilot rod's tunnel, from the exit pit to the entry pit, it too will be misaligned.
Because the coring rod is the rod that guides the piping into its desired location in the site, if the coring rod is misaligned, the piping will be misaligned. Accordingly, when a coring rod becomes misaligned it must be realigned before it can be used for its intended purpose.
The methods already known of realigning a coring rod, involve digging a tunnel from the exit pit, back into the site along the originally anticipated path of the pilot rod, and making that tunnel large enough that it connects, along its length, with the misaligned tunnel created by the pilot rod. The end result is a much larger than necessary tunnel, which encompasses the tunnel originally anticipated for the pilot rod, from its point of deviation to the exit pit. The coring rod can then be pulled back through the site, from the exit pit to the entry pit, travelling all the way along its originally anticipated path, by traveling through the portion of the larger than necessary tunnel that incorporates its originally anticipated path, up to the point of deviation, and then from that point, by traveling through the pilot rod created tunnel, which from that point back to the entry pit, is the originally anticipated tunnel. The methods that require the digging of unnecessarily large tunnels to connect up with a deviated pilot rod tunnel, have the obvious disadvantage that they require a great deal of excavation and earth moving that would not be necessary if the pilot rod had not deviated from its anticipated path.
An object of the present invention, is to provide a realignment tool that will allow a misaligned coring rod of the type described in co-pending application no. 08/320,751 to be realigned.
A second object of the present invention, is to provide a realignment tool that is relatively inexpensive to construct.
A third object of the present invention, is to provide a realignment tool that will be durable.
A fourth object of the present invention, is to provide a realignment tool that is easy to use.
A fifth object of the present invention, is to provide a realignment tool that will allow the coring rod to be realigned without having to pull it all the way through the site.
A sixth object of the present invention, is to provide a realignment tool that will allow the coring rod to be realigned after it has only been pulled back through the site to the point where the misalignment occurred.